The present invention relates generally to pressure responsive compressor valve assemblies and more particularly to such assemblies employing disc type valve members and particularly adapted for use on refrigeration compressors.
The present invention is particularly well suited for use in combination with the disc like lightweight valves of the type disclosed in assignee's application Ser. No. 971,309, filed Dec. 20, 1978 now abandoned in favor of continuation application Ser. No. 219,849, filed Dec. 23, 1980, now Pat. No. 4,368,755 and the head and valve plate of assignee's copending application Ser. No. 114,346, filed Jan. 22, 1980 and represents an alternative to the coil spring biasing arrangements of assignee's copending application Ser. No. 114,345, filed Jan. 22, 1980. It may be used in both rotary and other types of compressors including single and multi-cylinder reciprocating piston type compressors of either hermetic or accessible hermetic type.
Valve plates and cylinder head assemblies can become relatively complex in configuration for certain valve arrangements and as a result may be quite costly to manufacture and sometimes to assemble.
The present invention provides an improved valve plate assembly including a valve biasing arrangement which utilizes one or more leaf springs of the curved disc type in combination with a supporting bridge member having a plurality of guide fingers operative to guide movement of the disc valve member and to retain the valve and leaf spring in relative position. The use of this improved spring biasing member provides numerous advantages over prior coil spring type biasing arrangements. For example, because the leaf spring of the present invention provides a variable spring rate, the required preloading on the valve member when in a closed position may be reduced thereby reducing residual stress on the valve member. Similarly, the spring rate of the leaf spring may be lower for the initial opening of the valve member. Further, it is possible to easily control or vary the preloading and spring rate for different compressors by merely increasing the number of leaf springs incorporated in the valve assemblies. Additionally, when multiple leaf springs are employed, the frictional forces acting between the leaves provides a damping action which is particularly desirable to eliminate vibration of the valve member at high frequency operation as well as providing a redundancy so as to assure continued operation even in the event one of the leaf springs should fail.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.